US300036A - Valve-gear - Google Patents

Description

2 Sheets-Sheet 1. L. WINDHURST.

* VALVE GEAR.

(No Model.)

N0. 300,036. Patented June 10, 1884.

' Attest 9 L YAZJM N. PETERS. Photo-Lithographer. Washington. Dv Q UNTTED TATEs PATENT @rrrca.

LEWVIS \VINDHUR-ST, OF SPRINGFIELD, OHIO.

VALVE- GEAR.

SPECIFICATION forming part of Letters Patent No. 300,036, dated June 10, 1884.

Application filed October 6, 1883. (No model.)

To CLZZ whom it ntay concern.- Be it known that I, LEWIS WINDHURST, o Springfield, county of Clark, State of Ohio, have invented a new and useful Improvement in Valve-Gear for Direct-Acting Engines, of which the following is a specification.

The object of my invention is to produce a valve-motion for direct-acting engines, which first does away with auxiliary steam-piston valves as being complicated and hard to keep in order, second, moves the slide-valve similar to an eccentric, causing a gradual opening and closing of ports; third, does this with the least friction; fourth, avoids wear of small surfaces exposed to great pressure; and, fifth, admits'their adjustment if they do wear. I accomplish this by the arrangement shown in the accompanying drawings, in which all minor details of mechanical execution are omitted for simplicity. (See Section XII and note to Section III.) Figure 1 shows an elevation; Fig. 2, a horizontal section without the stea1n-cylinder, &c., the rod U B being hid by the rod IL Figs. 3 and 4 show elevations at different parts of stroke. Fig. 5 shows a partial side view explaining the parts S T, (like S T;) and Fig. 6 shows the main lever A A by itself.

Section I. In all figures, A A show a rock ing lever turning on the fixed center B, moving the valve V by the valve-rod U B. a a are the ports, W the piston, and H the pistonrod, all plainly as usual. F F are two links, joined atGGto the piston-rod, (directly Orindirectly by cross-heads or other attachments.) These links extend from G to S and G to S, and are, for simplicity of explanation, shown provided at e c with pins working in slits E D and E D of the above main lever A A. These slits are shaped nearly as shown, but which shape maybe varied to best accomplish the purpose to be described afterward. The main portion of these slits extends from the corners E and E to D and D, the latter ones being slightly widened or extended to I and I, respectively. T and T are projections of the main lever, cast on or separately attached.

The links have corresponding projections to meet them, at S S. (Best seen in the partial side view, Fig. 5, and in the other views under the points S S.) These latter projections, at

parts of the stroke, slide along under either T or T, and at other times sweep around over them, as in Fig. 3 at S.

Section II. I? is a forked branch of link F, serving to move up or down the roller 0 on the centerpin, N, in the wide slit L, (instead of which slit, in a varied mode of construction, may be only an are or slide fastened to the proper side of the main lever for that roll to travel on.) This roller and center N occupy the end of the pushing-rod K, which is here shown as pushedby a steam-plunger, f, or piston, (best for large engines,) but which can in small engines be replaced by a spring or other power, making pressure at the point N, always tending (if free to act) to turn the main lever in a certain direction, depending on the situation of the point N (roller 0) either below the centerB, as shown in Fig. 1, or above the center B, as shown in Fig. 4..

Section III. This roller 0, being moved by the fork P of the link F, always accompanies every motion of the piston-rod, standing highest when the piston XV is at the extreme outstroke, Fig. 4, standing lowest at the extreme instroke, Fig. l. [N ote: It is obvious thatwe attain the same object by leaving the fork P out and joining the center N by a separate link to the piston-rod at or near G, though not as simple] Section IV. Now, it will be seen that the lever A A (and consequently the slide-valve) is moved or turned by two different forces by the piston-rod and links as far as the deadpoint of the valve, (when it covers both ports,) and after that by a slight extra amount, enough to .open one port, by the force applied by rod K or roller 0, pressing against the central side of the slit L, (or an equivalent are or slide, as

said in Section II,) this force being set free to act just at that time, as will be presently shown.

Section V. Taking Fig. 1, we see the piston W and all parts connected thereto at the almost extreme instroke, and the main lever in a position corresponding to the dead-point of the valve, (it covering both ports a a,) the acting points or pins 0 e of the linksF F resting' in the corners D D of the slits E D and E D, the upper part, S, of link F (as it moves contrary to the piston-rod) just ready to escape from under T, these parts acting as a time-lock, setting free the power of the roller exerted on the main lever, and readily corrected by fixing or adjusting T in its proper place to take up wear.

Section VI. The lower surface of T being an are described from corner D, (the same as to T and D,) it follows that while the link F rests with its center 0 in the corner D, either.

' is free to act, forcing down the arm A a little more, thus moving the valve outward a little more than shown in Fig. 1, and opening port a. At the same time arm A would rise a little, moving corner I against the pin 0 of link F.

In fact, if this corner I (respectivelyI for the opposite extreme stroke) were not cut out for this purpose, link F would, by the pin 6, pre vent the main lever from moving under the action of roller 0. This act,which is j ust about to occur in Fig. 1, is shown as having occurred in the position for the opposite end of stroke in Fig. 4, to be referred to again.

Section VIII. Supposing,now,in Fig. 1,that this had occurred there, and thereby the port a partly opened, then the piston-rod moves outward like the lower dotted arrow, link F pushes up the arm A, as it always maintains a direction almost squarely against the surface of the slit at or near D, while the pin 0 of link F (its direction being too slant to impinge) glides up into slit D E, which went down of course as D E went up, until the whole reaches position Fig. 8, the projection of S sweeping around T in the direction of the arrow, T pass ing freely under end 6 S of link F. Both F and F have here attained their most upright positions. After this, on the last half of the outstroke, the points 6 and a go down again, 0 pulling down arm A at the corner D, arm A going up, not impeded by link F, which slides down again in slit D E, until nearly the position Fig. 4 is reached, then pins 6 e taking their original places at D and D, the links at first taking the-place of the dotted lines X X, (though the difference from the later position, F F in Fig. 4, is exaggerated.)

Section IX. While link F is pulling down at D, going from position 3 to position 4, even if the pin 6 should slide from corner D into corner I, it would pull down nearly the same; but even this is prevented, for during this time the upper end, S, is sweeping under projection T, (seen in side View, Fig. 5,) which tends to keep the pin in the corner D. As F approaches its position in Fig. 4., S, resting under T, forms a time-lock for this end of the stroke until it reaches the position X, when S escapes from under T and roller 0 turns the main lesoaoss ver into the shown position, where arm A has jumped down a small extra amount beyond the pulling of F. Arm A is raised accordingly, the corner D with it, the pin 6 of link F resting against corner I, and port a opened a certain amount for the return-stroke.

Section X. How much this extra amount of motion is, and consequently how much initial opening port a gets, is determined by the play of the pin e between the corners D I, for if there were no play, or, in other words, if the slit were not cut out to I, (as already mentioned, Section VII,) corner D would be under the center 0, this keeping in that case the le-' ver from turning more than pulled down by link F, which would be insufficient to go over the dead-point. Further, while corner D moved up from pin a, corner I moved up in contact with it as far as the lever can turn, thus limiting, also, the amount the other arm, A, can go down, the slit E D sliding down a little over the pin 6.

Section XI. Fig. 4: also shows the whole ready to begin the return instroke, (like the dotted arrow below H.) Link F first moves up the pin 0 in contact at D, being new directed squarely against that surface, then pushes up arm A, and moves down the roll 0, also moves down the arm A, with slit E D freely sliding down over pin 0 of link F,and after the highest point of e c is reached F will pull the main lever in the opposite direction, arm A, with slit E D, going up again unrestrained by F, but the roll 0 steadily down until the position Fig. 1 is reached,when the whole move ment is repeated. 7

Section XII. Referring back to Section IX, as to a possibility of the pins 6 e slipping out of the corners D D when they'ought to keep there, (in pushing or pulling,) this is most easily prevented by joining the links anywhere at their upper or middle parts by an elastic cross-piece or spring tending to press them apart; but I have not yet found necessity for it, the own weight of the links keeping them there in pushing and the aforesaid time-lockin pulling. Therefore such means are not indicated in the drawings.

Section XIII. Of course, this whole valvegear can be varied by putting the parts in different relative positions, or by applying the power of K in a different direction, or by applying spring, water, or compressed-air pressure instead of steam-pressure, leaving that part to the option of the manufacturer; nor is the shape of those slits or grooves important, as long as the portion near D D presents its surface at nearly right angles to the active link and the other portions allow the passive link to slide along them with the least resistance. I am aware that previous to my invention such contrivances as a steam-acted plunger, f, or a spring, have been used for similar purposes as above. Therefore I do not claim such as my invention; but

What I do claim, and intend to'secure by Letters Patent, is as follows:

1. The combination of the rocking lever A A, the links F F, slots or grooves E D E D, the time-locking contrivance T S T S, with an automatic device for operating the lever A A, and means for applying the action of said device to either side of the rocking center B, substantially as described.

2. In a valvegear, the combination of a double-armed rocking lever provided with a slot or groove at each arm, and the links FF, provided with the pins 0 a, with means for operating these links, the slots being so constructed and arranged that each link will actuate'the rocking lever only when moved by the pistonrod in a certain direction, as shown and described. V

3. In a valve gear, the combination of a double-armed rocking lever with two links, F F, one end of which links is operated by the piston-rod, the respective opposite end of said links being connected to an arm of the rock ing lever in such a manner that only one link can actuate said lever during the outstroke of the piston, and the opposite link only during the instroke of the piston, all substan- 'tially and for the purpose as set forth.

or the other of the-rocking center B, (in conformity to ,the motion of the piston-rod H,) with a time lock represented by the parts '1 S T S, so contrived as to restrain and limit the action of said extra power to the deadpoints of the slide-valve, substantially as set forth.

5. In a valve gear, the combination of a steam-plunger with a rocking lever and means for transferring the lever-connections of the steam-plunger or the spring to either side of the rocking center of the lever, substantially as described.

6. In a valve-gear, the combination of links F F, provided with projections S S, with the lever A A, provided with projections '1 T, the piston-rod H, and means independent of the links for actuating the lever A A, whereby theindependent means for actuating the lever A A is restrained until the piston has arrived at the end of a stroke, substantially as described.

7. The combination of the rocking lever A A, the links F F, slits or grooves E D E D, and the time-lock contrivance 'I S T S,with the extra moving power applied at N, and with means of transferring the same to either side of the rock-center B, substantially and for the purpose as described.

Intestimony whereof I have hereunto set my hand this 4th day of October, 1883.

LEWIS WINDHURST. \Vitnesses:

, Rurus M. GELwroKs,

GEORGE W. FIsH.

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